As the service requirements (such as multimedia call, file downloading, web browse, and streaming service) of users and operators are diversified, the network resources need to bear huge quantities of transmission services that require different Quality of Service (QoS) levels. To enable the limited network resources to bear such transmission services and exercise effective control on the transmission services that require different QoS levels, the policy control may be combined with the charging control to meet the urgent need of diversifying the profit models of operators; and Policy and Charging Control (PCC) architecture may be applied to meet different QoS control and charging requirements. In this way, the users have richer service experiences and operators have new growth points.
In the prior art, the PCC architecture includes a Policy and Charging Rules Function (PCRF), a Policy and Charging Enforcement Function (PCEF), and a Bearer Binding and Event Reporting Function (BBERF). A gateway control session is set up between the BBERF and the PCRF, and an IP-Connectivity Access Network (IP-CAN) session is set up between the PCEF and the PCRF; and a Diameter Routing Agent (DRA) (next-generation 3A protocol routing agent) associates the gateway control session and the IP-CAN session with the same PCRF according to the user identity (ID), and the PCRF associates the gateway control session with the IP-CAN session. In this way, it is ensured that the policy information is delivered to the corresponding gateway control session and the IP-CAN session, and that the user ID is globally unique, namely, it is impossible that two users use the same user ID. The user ID is stored in a Subscriber Identity Module (SIM) or a Universal Subscriber Identity Module (USIM).
In the process of implementing the present invention, the inventor finds at least the following problems in the prior art:
The association between the gateway control session and the IP-CAN session in the prior art is based on the user ID, and the user ID is stored in a SIM/USIM card; when an emergency service occurs, the SIM/USIM card may not exist or be invalid, namely, no user ID exists. Consequently, the DRA is unable to select different PCRFs according to different users; the PCRF is unable to associate the gateway control session with the IP-CAN session of the same user and unable to deliver policies correctly; and the QoS of the emergency service is not ensured.